BATON ROUGE - New research shows the LSU Campus Mounds, one of the college's most significant landmarks, are some of the oldest man-made structures in all of North America.

LSU shared details Monday from the study by the American Journal of Science, saying a charred mammal bone fragment that appears to be thousands of years old was among the factors that helped researchers more accurately date the structure. 

"Radiocarbon dating of the layers of material indicates the mounds were built over thousands of years. These findings show that people began to build the first mound about 11,000 years ago," the statement from LSU read in part.

The pair of roughly 20-foot mounds, built by indigenous people, are among more than 800 similar hill-like structures across Louisiana. While many of those mounds have been destroyed, LSU has made efforts to preserve its mounds, listed on the National Register for Historic Places. 

“The people who constructed the mounds, at about 6,000 years ago, coordinated the structures’ orientation to align with Arcturus, seen in the night sky at that time,” said Professor Emeritus Brooks Ellwood.

Read more about the mounds and the study here.